Monitors renewed

DIFFUSION tubes which help monitor levels of pollution in Henley have been approved for another six months. 

The devices, which were installed at six locations in December, were bought by Henley Town Council to help identify areas with high concentrations of nitrogen dioxide.

They cost £200 for six months, including the analysis of the results.

The tubes are located at Crew Clothing in Bell Street, the junction of New Street and Bell Street, the Marlow Road roundabout, the Kenton Theatre in New Street, the slipway at the bottom of New Street and on the side of Henley Bridge.

The tubes contain a steel mesh disc coated with triethanolamine, which absorbs nitrogen dioxide. After three months, the mesh is removed and washed with distilled water, which is then analysed.

The concentration of nitrogen dioxide is found by shining ultra violet light through the water sample.

Air quality campaigner David Dickie, of St Katherine’s Road, investigated the costs of the diffusion tubes last year and helped the council choose the locations.